test(all) add new harness tests

[darklight3it]

• chore: add pre commit script for anyone that wants to use it.
• chore: adding new tests

📬 Issue #, if available:

✍️ Description of changes:

Introducing some new harness tests on non concurrent tasks.

🔏 By submitting this pull request

• I confirm that I've ran cargo +nightly fmt.
• I confirm that I've ran cargo clippy --fix.
• I confirm that I've made a best effort attempt to update all relevant documentation.
• I confirm that my contribution is made under the terms of the Apache 2.0 license.